Multilayer Windings Effect on Interior PM Machines for EV Applications

Abstract

This paper mainly studies the effect of the winding layer number on the performance of interior permanent-magnet (IPM) synchronous machines equipped with fractional-slot concentrated windings (FSCWs) for electric vehicle applications. In order to quantitatively evaluate FSCW-IPM machines with different numbers of winding layers, three models with single-, double-, and four-layer winding configurations have been built to compare back electromagnetic force, average torque, torque ripple, core losses, copper losses, flux-weakening capability, overload capability, etc. Both theoretical and finite-element analysis results illustrate that multilayer windings yield lower d-axis inductance and weaker flux-weakening capability but better overload capability. It is also shown that torque ripple and core losses are significantly reduced in machines with multilayer windings.Index Terms-Electric vehicles (EVs), finite-element analysis (FEA), flux weakening, fractional slot, multilayer windings, permanent-magnet machines.

A Review of Integrated On-Board EV Battery Chargers: Advanced Topologies, Recent Developments and Optimal Selection of FSCW Slot/Pole Combination

“…Considerable reported work has been aimed at reducing the effect of eddy current loss, the associated noise, and undesirable vibration due to sub, super, and slot harmonics [90], [97], [109]. Compared to the different slot harmonics suppression techniques, the concept of stator shifting has recently been considered as the most effective solution to suppress the effect of slot harmonics [90], [97].…”

Coil- and phase-flux-linkage characteristics of dual excited permanent magnet machijnes equipped with different winding configurations

“…Li et al [5] show that the losses of fractional slot concentrated-winding PM machines reduces with increasing number of winding layers, although the lower winding-layer machines would produce higher electromagnetic output torque. In contrast, a study in [6] shows that the multi-layer wound machines are capable of producing larger torque than the singlelayer ones, owing to their higher values of reluctance torque and saliency ratios. In addition, the multi-layer wound machines have reduced torque ripple and enhanced overload withstand capability compared to the single-layer ones; albeit with increased mechanical complexity.…”

Influence of design parameters on flux‐weakening performance of interior permanent magnet machines with novel semi‐overlapping windings

“…3, a high degree of freedom exists when designing a rotor for IPM machines with V‐shaped PMs. Investigated design parameters are chosen as a result of experience gained through numerous investigations and comprehensive literature [6–48]. On the other hand, other key parameters, such as stator outer diameter, stator slot geometry, shaft diameter, air‐gap length, , and have not been considered in this paper because of these reasons: (i) their predicted obvious and/or insignificant effects (particularly due to the leakage flux); (ii) limited effects as a consequence of existing of mechanical constrains; (iii) their very limited range; (iv) not reasonable or possible to investigate its individual effect.…”

“…The steady state and FW performance characteristics of IPM machines are primarily affected by magnetic design, depending on stator/rotor topology and excitation, and sophisticated FW control techniques. From magnetic design point of view, extensively employed performance improvement methods, particularly for FW operation, are classified as follows: Winding topologies [10–16]; PM layer number, shape and position [17–23]; Flux barrier configuration and position [24–29]; PM segmentation [19, 30–34]; PM skewing [35–38]; Novel rotor topology [39–41]; Rotor shape optimisation [42–45]; Other techniques, such as excitation, axial lamination, damper bars and so on [31, 46–48]. …”